Characterization of 17 Capsicum varieties by evaluation of their apocarotenoid profile by Nexera UC

Importance of the Topic

Apocarotenoids are key oxidative cleavage products of carotenoids with significant roles in plant physiology, food quality and human health. They contribute to color, antioxidant properties and signaling functions, while established pigments like bixin and crocetin highlight their commercial relevance as food colorants and nutraceuticals. Profiling native apocarotenoids in dietary sources supports nutritional assessments and quality control across the food industry.

Objectives and Overview

This study presents the application of an online supercritical fluid extraction and chromatography coupled to triple quadrupole mass spectrometry (SFE-SFC-MS/MS) method to characterize native apocarotenoids in seventeen Capsicum varieties. The goals were to qualitatively identify free and esterified apocarotenoids and to obtain selected quantitative data for prominent analytes across different species (C. annuum, C. baccatum, C. chinense).

Methodology and Instrumentation

• Sample Preparation: Fresh chilli sample (~0.85 g) homogenized with Miyazaki Hydro-Protect adsorbent to remove water and generate fine granules.
• SFE Conditions: CO₂ and methanol modifier (10 % static, 0 % dynamic), extraction vessel at 80 °C, 15 MPa, flow rate 2 mL/min.
• SFC Conditions: Fused core C30 column (150 × 4.6 mm, 2.7 µm), gradient from 0–80 % methanol, 2 mL/min, make-up methanol at 1 mL/min, back pressure 15 MPa.
• Detection: APCI source on triple quadrupole mass spectrometer operating in SCAN, SIM and MRM modes for positive and negative ions.

Instrumentation Used

Shimadzu Nexera UC system comprising dual CO₂ pumps, back pressure regulators, column oven, autosampler and LCMS-8050 triple quadrupole with APCI interface, controlled by LabSolutions™ ver. 5.80.

Main Results and Discussion

• Identification: 19 free apocarotenoids and 8 fatty acid esters detected across 17 cultivars, including mono- and diesters.
• Species Variation: β-citraurin predominantly in C. chinense; absent in C. baccatum. Apo-8’-carotenal widespread, present in 12 of 17 samples.
• Ester Profile: Lauric acid esters of Apo-10’ and Apo-8’-zeaxanthinal most abundant; caproic esters limited to specific cultivars.
• Quantification: β-citraurin ranged 8.7–61.0 mg/100 g; apo-8’-carotenal from 4.9–33.6 mg/100 g; highest levels in Habanero Red Savina.
• First Reports: Detection of ε-apoluteinals and 4-oxo-apo-β-carotenals in any food matrix.

Benefits and Practical Applications

Profiling native apocarotenoids enhances understanding of varietal quality traits, supports selection in breeding programs, and enables natural colorant sourcing. Quantitative data facilitate nutrition labeling, functional food development and quality control in pepper-derived products.

Future Trends and Potential Applications

• Expansion to a wider range of foods and vegetables for comprehensive apocarotenoid databases.
• Integration with metabolomics and chemometric tools for detailed profiling and authentication.
• Automation of extraction and analysis workflows for high-throughput screening in breeding and quality assurance.
• Investigation of biological activities to develop novel nutraceuticals and functional ingredients.

Conclusion

The online SFE-SFC-MS/MS approach on the Nexera UC platform allowed rapid and comprehensive characterization of free and esterified apocarotenoids in chili peppers. The study revealed species-specific profiles and novel compounds, demonstrating the method’s potential for routine nutritional and quality analyses in the food industry.